[Modbus] 如何 用 C# 開發 Modbus Master Protocol - (04) 實作 TcpModbusRequest
續上篇，接下來，我要實作Modbus TCP 的 Request Protocol
這也沒有太大的困難，只要建立符合標準的通訊協定就可以了，在這裡我利用 MemoryStream 來建立我想要組合的通訊協定，若對組合通訊協定有問題，請參考
另外我在功能裡自動累加 TransactionID ，它是一個身份識別的位置，可有可無，若不需要的話自行拿掉。
程式碼如下：
internal class TcpModbusRequest : AbsModbusRequest
{
private ushort? _transaction;
private readonly ushort MODBUS_PROTOCOL = 0;
private readonly ushort MODBUS_DEFAULT_LENGTH = 6;
private byte[] createReadMessage(byte Unit, EnumModbusFunctionCode FunctionCode, ushort StartAddress, ushort Quantity)
{
if (this.TransactionID != null)
{
this._transaction = TransactionID;
}
if (this._transaction == null)
{
this._transaction = 0;
}
using (MemoryStream memory = new MemoryStream())
{
memory.WriteByte((byte)(this._transaction >> 8));
memory.WriteByte((byte)this._transaction);
memory.WriteByte((byte)(MODBUS_PROTOCOL >> 8));
memory.WriteByte((byte)MODBUS_PROTOCOL);
memory.WriteByte((byte)(MODBUS_DEFAULT_LENGTH >> 8));
memory.WriteByte((byte)MODBUS_DEFAULT_LENGTH);
memory.WriteByte((byte)Unit);
memory.WriteByte((byte)FunctionCode);
memory.WriteByte((byte)(StartAddress >> 8));
memory.WriteByte((byte)(StartAddress));
memory.WriteByte((byte)(Quantity >> 8));
memory.WriteByte((byte)(Quantity));
this._transaction++;
return memory.ToArray();
}
}
public override byte[] ReadCoils(byte Unit, ushort StartAddress, ushort Quantity)
{
this.QuantityValidate(StartAddress, Quantity, 1, 2000);
var requestArray = this.createReadMessage(Unit, EnumModbusFunctionCode.ReadCoils, StartAddress, Quantity);
return requestArray;
}
public override byte[] ReadDiscreteInputs(byte Unit, ushort StartAddress, ushort Quantity)
{
this.QuantityValidate(StartAddress, Quantity, 1, 2000);
var requestArray = this.createReadMessage(Unit, EnumModbusFunctionCode.ReadDiscreteInputs, StartAddress, Quantity);
return requestArray;
}
public override byte[] ReadHoldingRegisters(byte Unit, ushort StartAddress, ushort Quantity)
{
this.QuantityValidate(StartAddress, Quantity, 1, 175);
var requestArray = this.createReadMessage(Unit, EnumModbusFunctionCode.ReadHoldingRegisters, StartAddress, Quantity);
return requestArray;
}
public override byte[] ReadInputRegisters(byte Unit, ushort StartAddress, ushort Quantity)
{
this.QuantityValidate(StartAddress, Quantity, 1, 175);
var requestArray = this.createReadMessage(Unit, EnumModbusFunctionCode.ReadInputRegisters, StartAddress, Quantity);
return requestArray;
}
public override byte[] WriteSingleCoil(byte Unit, ushort OutputAddress, bool OutputValue)
{
ushort outputValue = 0x0000;
if (OutputValue)
{
outputValue = 0xFF00;
}
if (this.TransactionID != null)
{
this._transaction = TransactionID;
}
if (this._transaction == null)
{
this._transaction = 0;
}
using (MemoryStream memory = new MemoryStream())
{
memory.WriteByte((byte)(this._transaction >> 8));
memory.WriteByte((byte)this._transaction);
memory.WriteByte((byte)(MODBUS_PROTOCOL >> 8));
memory.WriteByte((byte)MODBUS_PROTOCOL);
memory.WriteByte((byte)(MODBUS_DEFAULT_LENGTH >> 8));
memory.WriteByte((byte)MODBUS_DEFAULT_LENGTH);
memory.WriteByte((byte)Unit);
memory.WriteByte((byte)EnumModbusFunctionCode.WriteSingleCoil);
memory.WriteByte((byte)(OutputAddress >> 8));
memory.WriteByte((byte)(OutputAddress));
memory.WriteByte((byte)(outputValue >> 8));
memory.WriteByte((byte)(outputValue));
this._transaction++;
return memory.ToArray();
}
}
public override byte[] WriteSingleRegister(byte Unit, ushort OutputAddress, short OutputValue)
{
if (this.TransactionID != null)
{
this._transaction = TransactionID;
}
if (this._transaction == null)
{
this._transaction = 0;
}
using (MemoryStream memory = new MemoryStream())
{
memory.WriteByte((byte)(this._transaction >> 8));
memory.WriteByte((byte)this._transaction);
memory.WriteByte((byte)(MODBUS_PROTOCOL >> 8));
memory.WriteByte((byte)MODBUS_PROTOCOL);
memory.WriteByte((byte)(MODBUS_DEFAULT_LENGTH >> 8));
memory.WriteByte((byte)MODBUS_DEFAULT_LENGTH);
memory.WriteByte((byte)Unit);
memory.WriteByte((byte)EnumModbusFunctionCode.WriteSingleRegister);
memory.WriteByte((byte)(OutputAddress >> 8));
memory.WriteByte((byte)(OutputAddress));
memory.WriteByte((byte)(OutputValue >> 8));
memory.WriteByte((byte)(OutputValue));
this._transaction++;
return memory.ToArray();
}
}
public override byte[] WriteMultipleCoils(byte Unit, ushort StartAddress, ushort Quantity, byte[] OutputValues)
{
this.QuantityValidate(StartAddress, Quantity, 1, 0x07B0);
byte counter = base.GetByteCount(Quantity);
if (counter != OutputValues.Length)
{
ModbusException.GetModbusException(0x03);
}
if (this.TransactionID != null)
{
this._transaction = TransactionID;
}
if (this._transaction == null)
{
this._transaction = 0;
}
ushort dataLength = (ushort)(MODBUS_DEFAULT_LENGTH + OutputValues.Length + 1);
using (MemoryStream memory = new MemoryStream())
{
memory.WriteByte((byte)(this._transaction >> 8));
memory.WriteByte((byte)this._transaction);
memory.WriteByte((byte)(MODBUS_PROTOCOL >> 8));
memory.WriteByte((byte)MODBUS_PROTOCOL);
memory.WriteByte((byte)(dataLength >> 8));
memory.WriteByte((byte)dataLength);
memory.WriteByte((byte)Unit);
memory.WriteByte((byte)EnumModbusFunctionCode.WriteMultipleCoils);
memory.WriteByte((byte)(StartAddress >> 8));
memory.WriteByte((byte)(StartAddress));
memory.WriteByte((byte)(Quantity >> 8));
memory.WriteByte((byte)(Quantity));
memory.WriteByte((byte)(counter));
memory.Write(OutputValues, 0, OutputValues.Length);
this._transaction++;
return memory.ToArray();
}
}
public override byte[] WriteMultipleRegisters(byte Unit, ushort StartAddress, ushort Quantity, short[] OutputValues)
{
this.QuantityValidate(StartAddress, Quantity, 1, 0x007B);
byte[] outputArray = base.GetByteCount(OutputValues);
byte counter = (byte)outputArray.Length;
if (Quantity * 2 != outputArray.Length)
{
ModbusException.GetModbusException(0x02);
}
if (this.TransactionID != null)
{
this._transaction = TransactionID;
}
if (this._transaction == null)
{
this._transaction = 0;
}
ushort dataLength = (ushort)(MODBUS_DEFAULT_LENGTH + counter + 1);
using (MemoryStream memory = new MemoryStream())
{
memory.WriteByte((byte)(this._transaction >> 8));
memory.WriteByte((byte)this._transaction);
memory.WriteByte((byte)(MODBUS_PROTOCOL >> 8));
memory.WriteByte((byte)MODBUS_PROTOCOL);
memory.WriteByte((byte)(dataLength >> 8));
memory.WriteByte((byte)dataLength);
memory.WriteByte((byte)Unit);
memory.WriteByte((byte)EnumModbusFunctionCode.WriteMultipleRegisters);
memory.WriteByte((byte)(StartAddress >> 8));
memory.WriteByte((byte)(StartAddress));
memory.WriteByte((byte)(Quantity >> 8));
memory.WriteByte((byte)(Quantity));
memory.WriteByte((byte)(counter));
memory.Write(outputArray, 0, outputArray.Length);
this._transaction++;
return memory.ToArray();
}
}
}
建立單元測試，確保方法如期執行。
那驗証如何取得?取了手動建立外，還可以由其他工具取得，請參考上篇，[Modbus] 如何 用 C# 開發 Modbus Protocol - (1) 事前準備
private ModbusUtility _modbusUtility = new ModbusUtility();
[TestMethod()]
public void ReadCoilsTest()
{
TcpModbusRequest target = new TcpModbusRequest();
byte Unit = 1;
ushort StartAddress = 0;
ushort Quantity = 10;
ushort Transaction = 0;
byte[] expected = _modbusUtility.HexStringToBytes("00 00 00 00 00 06 01 01 00 00 00 0A");
target.TransactionID = Transaction;
byte[] actual;
actual = target.ReadCoils(Unit, StartAddress, Quantity);
Assert.IsTrue(expected.SequenceEqual(actual));
}
[TestMethod()]
public void ReadDiscreteInputsTest()
{
TcpModbusRequest target = new TcpModbusRequest();
byte Unit = 1;
ushort StartAddress = 0;
ushort Quantity = 10;
ushort Transaction = 0;
byte[] expected = _modbusUtility.HexStringToBytes("00 00 00 00 00 06 01 02 00 00 00 0A");
byte[] actual;
target.TransactionID = Transaction;
actual = target.ReadDiscreteInputs(Unit, StartAddress, Quantity);
Assert.IsTrue(expected.SequenceEqual(actual));
}
[TestMethod()]
public void ReadHoldingRegistersTest()
{
TcpModbusRequest target = new TcpModbusRequest();
byte Unit = 1;
ushort StartAddress = 0;
ushort Quantity = 10;
ushort Transaction = 0;
byte[] expected = _modbusUtility.HexStringToBytes("00 00 00 00 00 06 01 03 00 00 00 0A");
byte[] actual;
target.TransactionID = Transaction;
actual = target.ReadHoldingRegisters(Unit, StartAddress, Quantity);
Assert.IsTrue(expected.SequenceEqual(actual));
}
[TestMethod()]
public void ReadInputRegistersTest()
{
TcpModbusRequest target = new TcpModbusRequest();
byte Unit = 1;
ushort StartAddress = 0;
ushort Quantity = 100;
ushort Transaction = 934;
byte[] expected = _modbusUtility.HexStringToBytes("03 A6 00 00 00 06 01 04 00 00 00 64");
byte[] actual;
target.TransactionID = Transaction;
actual = target.ReadInputRegisters(Unit, StartAddress, Quantity);
Assert.IsTrue(expected.SequenceEqual(actual));
}
[TestMethod()]
public void WriteSingleCoilTest()
{
TcpModbusRequest target = new TcpModbusRequest();
byte Unit = 1;
ushort OutputAddress = 0;
bool OutputValue = true;
ushort Transaction = 1106;
byte[] expected = _modbusUtility.HexStringToBytes("04 52 00 00 00 06 01 05 00 00 FF 00");
byte[] actual;
target.TransactionID = Transaction;
actual = target.WriteSingleCoil(Unit, OutputAddress, OutputValue);
Assert.IsTrue(expected.SequenceEqual(actual));
}
[TestMethod()]
public void WriteSingleRegisterTest()
{
TcpModbusRequest target = new TcpModbusRequest();
byte Unit = 1;
ushort OutputAddress = 2;
short OutputValue = 234;
ushort Transaction = 18;
byte[] expected = _modbusUtility.HexStringToBytes("00 12 00 00 00 06 01 06 00 02 00 EA");
byte[] actual;
target.TransactionID = Transaction;
actual = target.WriteSingleRegister(Unit, OutputAddress, OutputValue);
Assert.IsTrue(expected.SequenceEqual(actual));
}
[TestMethod()]
public void WriteMultipleCoilsTest()
{
TcpModbusRequest target = new TcpModbusRequest();
byte Unit = 1;
ushort StartAddress = 0;
ushort Quantity = 9;
byte[] OutputValues = new byte[] { 0x0E, 0x00 };
ushort Transaction = 895;
byte[] expected = _modbusUtility.HexStringToBytes("03 7F 00 00 00 09 01 0F 00 00 00 09, 02 0E 00");
byte[] actual;
target.TransactionID = Transaction;
actual = target.WriteMultipleCoils(Unit, StartAddress, Quantity, OutputValues);
Assert.IsTrue(expected.SequenceEqual(actual));
}
[TestMethod()]
public void WriteMultipleRegistersTest()
{
TcpModbusRequest target = new TcpModbusRequest();
byte Unit = 1;
ushort StartAddress = 0;
ushort Quantity = 10;
short[] OutputValues = new short[] { 78, 87, -78, -87, 23, 35, 123, 12, 33, 6 };
ushort Transaction = 0x03DA;
byte[] expected = _modbusUtility.HexStringToBytes("03 DA 00 00 00 1B 01 10 00 00 00 0A 14 00 4E 00 57 FF B2 FF A9 00 17 00 23 00 7B 00 0C 00 21 00 06");
byte[] actual;
target.TransactionID = Transaction;
actual = target.WriteMultipleRegisters(Unit, StartAddress, Quantity, OutputValues);
Assert.IsTrue(expected.SequenceEqual(actual));
}
若有謬誤，煩請告知，新手發帖請多包涵
Microsoft MVP Award 2010~2017 C# 第四季
Microsoft MVP Award 2018~2022 .NET
